US forces struck Iran for a ninth consecutive day on Monday ​as the number of confirmed American military deaths in the renewed fighting rose to three and concerns grew over shipping through the ‌Strait of Hormuz.

In a statement, US Central Command said it started “a new wave of strikes” aimed at “degrading” Iran’s ability to attack commercial vessels in the strait’s vital shipping lanes.

The Central Command announcement gave no further details.

But Iran’s semi-official Tasnim news agency, citing its own reporters, said US missiles struck several Iranian cities early Monday.

Explosions were heard in Tabriz, Chabahar, Konarak, Bandar Mahshahr and Bandar ​Imam Khomeini, according to Tasnim.

In the latest American casualty reported in the war, the US military said on Sunday that a service member was killed ​on Saturday in northern Iraq, where the US has military bases, during a controlled detonation of what Central Command called ⁠unexploded ordnance on a downed Iranian attack drone.

Earlier in the weekend, the US military said two of its service personnel died in Jordan and that a third was missing ​in action.

On Sunday, Central Command said in a statement that “unidentified remains” had been found at the site of Friday’s attack and that “an examination process to verify ​the remains is ongoing.”

The latest casualty announcements brought the total number of US military personnel killed since the war began to 17, with more than 420 others wounded.

For its part, Iran’s Islamic Revolutionary Guard Corps announced a surprise strike against “the enemy’s special operations headquarters in Syria’s Al-Tanf area.”

Iran earlier conducted a drone attack on US military assets and equipment at Kuwait’s Al Adiri camp ​and Ali Al Salem Air Base, Iranian state TV reported early on Sunday.

Iran had previously hit both bases as part of its attacks against US ​assets and allies in the Gulf over the past week.

Kuwait’s government said a desalination plant had been attacked for the second day running, causing a fire, in what it called a direct ‌strike on ⁠vital civilian infrastructure.

Concerns about the flow of energy supplies through the Strait of Hormuz have persisted since the United States and Iran resumed open hostilities after accusing each other of repeatedly violating a ceasefire deal.

The Royal Navy’s United Kingdom Maritime Operations Centre said late Sunday that it received a report that a vessel was on fire not far from the Omani coast, although it had not verified a cause.

Oil prices jumped 3% on Monday, with Brent crude futures surpassing $90 a barrel, the highest level ​since June 11.

Monday’s attacks came the day ​after Central Command said its eighth ⁠consecutive wave of attacks hit Iranian military coastal surveillance and air defence facilities.

The US and Iran have intensified attacks as an interim ceasefire agreement signed a month ago has unravelled, and a struggle for control of the Strait of Hormuz has ​deepened, raising the risk of a return to all-out hostilities.

“We hit them very hard again tonight, and we did it ​in honour of” ⁠the US service members killed since Friday, Trump told reporters after he returned from attending the World Cup final.

The US Embassy in the Gulf state of Bahrain warned that it had information suggesting Iran may seek to target unspecified locations in central Manama, that nation’s capital, and urged Americans there to remain vigilant.

The conflict, which began when the US ⁠and Israel ​attacked Iran on February 28, seeking to disable Tehran’s nuclear and missile programmes and weaken its regional proxies, has killed ​thousands of people, mostly in Iran and Lebanon, and led to major energy supply disruptions and fears over global inflation.